Three ringed planets labeled present, past and future, each with five empty boxes below, and fifteen word cards to cut from the bottom of the page. Five verbs appear in all three tenses: land, wave, float, watch and zoom, giving zoomed and will zoom and zooms, and so on across the set. An astronaut, a comet and a flying saucer fill the margins.
Because every verb shows up three times, the sort is self-checking. Five cards per planet, and any child who ends up with six under past knows to look again before the glue comes out. All five verbs are regular, so past tense is the -ed ending every time and the pattern stays visible.